Ensure an object meets expectations

stabilize_arg() is used by other functions such as stabilize_int(). Use stabilize_arg() if the type-specific functions will not work for your use case, but you would still like to check things like size or whether the object is NULL.

stabilize_arg_scalar() is optimized to check for length-1 vectors.

Usage

stabilize_arg(
  x,
  ...,
  allow_null = TRUE,
  allow_na = TRUE,
  min_size = NULL,
  max_size = NULL,
  unique = FALSE,
  x_arg = caller_arg(x),
  call = caller_env(),
  x_class = object_type(x)
)

stabilize_arg_scalar(
  x,
  ...,
  allow_null = TRUE,
  allow_zero_length = TRUE,
  allow_na = TRUE,
  x_arg = caller_arg(x),
  call = caller_env(),
  x_class = object_type(x)
)

Arguments

x

The object to stabilize.

...

Arguments passed to methods.

allow_null

(logical(1)) Is NULL an acceptable value?

allow_na

(logical(1)) Are NA values ok?

min_size

(integer(1)) The minimum size of the object. Object size will be tested using vctrs::vec_size().

max_size

(integer(1)) The maximum size of the object. Object size will be tested using vctrs::vec_size().

unique

(logical(1)) Should all elements in x be distinct?

x_arg

(character(1)) The name of the object being stabilized to use in error messages. The automatic value will work in most cases, or pass it through from higher-level functions to make error messages clearer in unexported functions.

call

(environment) The execution environment to mention as the source of error messages.

x_class

(character(1)) The class name of the object being stabilized to use in error messages. Use this if you remove a special class from the object before checking its coercion, but want the error message to match the original class.

allow_zero_length

(logical(1)) Are zero-length vectors acceptable?

Value

x, or an error condition with classes <stbl-error>, <stbl-condition>, <rlang_error>, <error>, <condition>, and a specific class by failure mode:

• <stbl-error-bad_null> for NULL values when allow_null = FALSE.

• <stbl-error-bad_na> for NA values when allow_na = FALSE.

• <stbl-error-size_too_small> when the vector is shorter than min_size.

• <stbl-error-size_too_large> when the vector is longer than max_size.

• <stbl-error-bad_empty> for empty vectors when allow_zero_length = FALSE in stabilize_arg_scalar().

• <stbl-error-non_scalar> for non-scalar vectors in stabilize_arg_scalar().

See also

Other stabilization functions: assert_present(), stabilize_any_of(), stabilize_chr(), stabilize_chr_scalar(), stabilize_date(), stabilize_date_scalar(), stabilize_dbl(), stabilize_dbl_scalar(), stabilize_df(), stabilize_dttm(), stabilize_dttm_scalar(), stabilize_dur(), stabilize_dur_scalar(), stabilize_fct(), stabilize_fct_scalar(), stabilize_int(), stabilize_int_scalar(), stabilize_lgl(), stabilize_lgl_scalar(), stabilize_lst(), stabilize_time(), stabilize_time_scalar(), to_chr(), to_chr_scalar(), to_date(), to_date_scalar(), to_dbl(), to_dbl_scalar(), to_dttm(), to_dttm_scalar(), to_dur(), to_dur_scalar(), to_fct(), to_fct_scalar(), to_int(), to_int_scalar(), to_lgl(), to_lgl_scalar(), to_time(), to_time_scalar()

Examples

wrapper <- function(this_arg, ...) {
  stabilize_arg(this_arg, ...)
}
wrapper(1)
#> [1] 1
wrapper(NULL)
#> NULL
wrapper(NA)
#> [1] NA
try(wrapper(NULL, allow_null = FALSE))
#> Error in wrapper(NULL, allow_null = FALSE) : 
#>   `this_arg` must not be <NULL>.
try(wrapper(NA, allow_na = FALSE))
#> Error in wrapper(NA, allow_na = FALSE) : 
#>   `this_arg` must not contain NA values.
#> • NA locations: 1
try(wrapper(1, min_size = 2))
#> Error in wrapper(1, min_size = 2) : 
#>   `this_arg` must have size >= 2.
#> ✖ 1 is too small.
try(wrapper(1:10, max_size = 5))
#> Error in wrapper(1:10, max_size = 5) : 
#>   `this_arg` must have size <= 5.
#> ✖ 10 is too big.
stabilize_arg_scalar("a")
#> [1] "a"
stabilize_arg_scalar(1L)
#> [1] 1
try(stabilize_arg_scalar(1:10))
#> Error in eval(expr, envir) : 
#>   `1:10` must be a single <integer>.
#> ✖ `1:10` has 10 values.